<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title></title>
    <style>
        .box {
            width: 140px;
            height: 140px;
            padding: 20px;
            border: 10px solid #000;
            background-color: gold;
            word-wrap: break-word;
            /* 字母数字强制换行 */
        }
    </style>
</head>

<body>
    <div class="box">
        啊啊啊啊啊啊啊
    </div>
</body>

</html>